Sleep–wake dynamics in veteran–service dog dyads: an exploration of overnight concordance

Study Objectives Sleep disturbances are well-documented for veterans with posttraumatic stress disorder. Increasingly, veterans are turning to service dogs for assistance. Service dogs may positively influence veteran sleep. However, there is a need for research that considers bidirectional sleep interactions at the dyad level. Our objective was to investigate overnight sleep–wake dynamics in veteran–service dog dyads. Methods Fifty-six veteran–service dog dyads contributed data for analysis. Standardized questionnaires were captured at baseline (veteran well-being, prior to service dog partnering) and at 3-month follow-up (dyad bond and well-being). Fourteen days of actigraphy (1 min epochs) and ecological momentary assessment (twice daily) were collected at follow-up. We calculated sleep–wake concordance (percent agreement; 0% to 100%) and activity concordance (Stuart–Kendall Tau-c; −1.0 to 1.0) from 650 nights of actigraphy data, including 289749 min-level observations. Results Based on a nightly average, veteran–service dog dyads had 79% sleep–wake concordance (range 63% to 88%) and 0.04 activity concordance (range −0.02 to 0.15). Service dogs exhibited higher sensitivity to veteran wakefulness (28%; range 9% to 82%) than veterans to service dogs (11%; range 4% to 21%). Regression analyses found no consistent relationships between concordance and measures of veteran–service dog bond or well-being. Conclusions Veteran–service dog dyads demonstrate sleep–wake concordance rates comparable to those reported in other close relationships (e.g. mother–infant, couples), and service dogs appear more sensitive to veteran wakefulness than the other way around. This novel investigation offers a framework for future research on human–service dog overnight dynamics, emphasizing the mutual attunement of veterans and their service dogs.